Study On Cooperatve Spectrum Sensing In Vehicular Ad Hoc Networks And The System Level Simulation

After rapid development of the wireless communications in recent years,its application fields have covered all aspects of people's life.Faced with the frequent traffic accidents and the increasingly heavy traffic congestion caused by the surge in the number of vehicles in today's society,the demand of building an intelligent transportation system,which is based on wireless communications technology,continues to grow.With the further research of the fifth generation mobile communication system,the Internet of vehicle networks has become a very important research scenario in 5G dominated by 3 GPP.Performance simulation evaluation has become a work that is highly valued in both academia and industry.The research on the key technologies required for the integration of vehicle self-organizing networks and cellular networks is particularly important.The use of spectrum sensing technology in vehicle networks can improve the efficiency of information exchange and ensure the reliability of data transmission.In order to be unified with international standards,optimization based on the standard of 3 GPP is an inevitable requirement from both of the theory and practice.This thesis first outlines the applications of the vehicle networks from application deployment scenarios to technical indicators,summarizes and analyzes the key technologies in the development of vehicle networks,including frame structure,resource allocation,synchronous signal design and the future researching direction of vehicle networks.Through the establishment of system models and signal distribution studies,the characteristics of cognitive wireless networks under the Vehicular Network and based on traditional cognitive radio technologies are optimized for energy detection schemes in terms of energy detection,and in the cooperative sensing mode.The secondary users' perception scheme in the perception process is further optimized.By adopting grouping and other designs,the perceived probability of the relevant channel is improved.In the field of vehicle network communication simulation,this paper designs and implements a system-level simulation platform based on LTE protocol.First of all,according to the 3GPP related protocol system,the channel model,data packet generation,transmission and reception are realized.At the same time,according to the characteristics of the vehicle networked communication process,for example,the mechanism of carrier-free such as schedule-free and perceptual process is realized,and finally the vehicle network communication simulation in highway scene is completed.By running the simulation program,the system produces the related performance results and makes a vehicle network system performance evaluation.The experimental results are in accordance with the relevant performance specifications in the protocol,and the simulation platform can complete the evaluation of vehicle networks performance.